International roaming is a mobile communication service enabling a user who subscribes to a mobile communication network (home network) having a certain country as a service area to communicate in the service area of a foreign mobile communication network similarly to the manner in which communication is performed in the home network.
Terminal roaming and chip roaming are known as international roaming methods. Terminal roaming is a method of using a mobile station (dual mobile station, composite mobile station) which is capable of communication even after moving (roaming out) from the home network to a foreign mobile communication network (see Japanese Published patent application No. 2001-119750).
Hereinafter, a mobile station which is capable of using at least both of a Japanese W-CDMA (Wideband Code Division Multiple Access) network and a European GSM (GSM: Global System for Mobile Communication) network, which are third generation international standards, will be described using terminal roaming as an example.
FIG. 13 is a block diagram showing an example of the hardware configuration of an international roaming-capable mobile station.
In the drawing, a control unit 106 comprises a CPU (Central Processing Unit), and by means of a control program and an application program stored in memory (ROM/RAM: Read Only Memory/Random Access Memory) 110, the control unit 106 controls a wireless transceiving unit 102 and a voice signal processing unit 103 to perform telephone call-making/call-receiving control and non-telephonic network connection control.
A detachable external memory card may be provided as a part of the memory 110.
The wireless transceiving unit 102 is compatible with a plurality of mobile communication modes (W-CDMA, CDMA2000, GSM).
The user selects one of the plurality of mobile communication modes by manipulating a key input unit 109 in accordance with his/her current position. The control unit 106 sets the internal configuration of the wireless transceiving unit 102 in accordance with the selected mobile communication mode.
The voice signal processing unit 103 subjects voice data demodulated by the wireless transceiving unit 102 to digital/analog conversion and outputs the converted voice data through a speaker (receiver) 104. Meanwhile, a voice signal input through a microphone (transmitter) 105 is subjected to analog/digital conversion and output to the wireless transceiving unit 102 for modulation.
Recent mobile stations have a function for receiving various non-telephonic services (content service) such as a content distribution service via a network.
The control unit 106 is also connected to a display unit 107, a digital camera unit 108, the key input unit 109, and an external interface 111, and thus controls Web page access, image capturing, games, electronic mail reception and transmission, and so on. The key input unit 109 performs content menu selection, distribution request input, and so on. The display unit 107 displays confirmation of key input operations, content menus, downloaded image content, and so on.
Here, content service is not limited to a service for receiving distributed content data, and also signifies the provision by a content provider server of various services corresponding to requests from a mobile station 1.
Accordingly, content service is not limited to the distribution of image data, music data, or programs for games or the like, and includes transaction data for securities transactions and the like, and cases in which money transfers into a bank account, electronic payment by credit card and the like, and so on are performed via a network.
However, when an attempt is made to provide international roaming-capable mobile stations with content service that is provided to stations for domestic use only, various problems occur.
FIG. 14 is an illustrative view showing problems associated with content service caused by international roaming.
In the drawing, 61 denotes an international roaming-capable mobile station.
121 denotes the service area of a domestic (Japanese) mobile communication network (home network), while 122 denotes the service area of a foreign (British, for example) mobile communication network.
123 denotes a server (Web server: World Wide Web server) of a bank (content provider) having a domestic (Japanese) office location, while 124 denotes a server (Web server) of a distribution company (content provider) having a domestic office location.
As a first problematic example, a case in which the mobile station 61 accesses the server 123 of the Japanese bank in order to transfer money into an account will be considered.
The mobile station 61 is located with the domestic service area 121, and hence no problem arises when accessing the server 123 of the Japanese bank via a domestic mobile communication network (wireless access network+core network) and the Internet.
However, when the mobile station 61 accesses the server 123 of the Japanese bank within the foreign service area 122, the country of the service area in which the mobile station 61 is located and the country in which the bank server 123 is located are different, and moreover, there is a time difference between the date and hour of the foreign country and the date and hour in Japan, leading to possible legal effects on the payment process.
As a second problematic example, a case in which the mobile station 61 accesses the server 124 of the Japanese distribution company, purchases copyrighted content, and downloads the content will be considered.
Various cases may be envisaged, such as a case in which the reproduction rights and public transmission rights of the content are contracted according to the country in which the user resides, or a case in which a contract may not have been signed with the country in which the user resides.
Hence, no particular problems arise when the mobile station 61 is within the Japanese service area 121 in which the distribution company has an office location. However, if the mobile station 61 requests content distribution from the distribution company server 124 when located in the foreign service area 122, the form of the service must be altered in accordance with the country in which the mobile station 61 is located in order to comply with the contractual relationship that has been established with that country in relation to the copyright of the content.
As described above, when no legal arrangements are made with regard to the date and hour, the copyright agreement of the distribution content, and so on, various problems arise. Hence, due to the inherent business risk, the content provider side tends to provide no services whatsoever to the international roaming-capable mobile station 61. As a result, the international roaming-capable mobile station 61 cannot receive same services to those provided to stations for domestic use only even when in Japan.
Under the 3GPP (3rd Generation Partnership Project) standard, the server side cannot learn the service area from which the international roaming-capable mobile station 61 performs access.
For comparison, a case in which a personal computer accesses a server by connecting to the Internet from an access point belonging to an Internet provider will now be considered. When the personal computer is connected to the access point, an IP (Internet Protocol) address is allocated to the personal computer by the Internet provider. By determining this IP address, even incompletely, the country in which the personal computer is located can be learned.
However, when the international roaming-capable mobile station 61 roams out to a foreign network, the IP address remains allocated to a switching node of the home network. Hence, even when the mobile station 61 is within the service area of another country, the IP address allocated to the mobile station 61 indicates the home country, and therefore the country of the service area in which the mobile station 61 is located remains unknown.